In Patent Document 1, a ram is provided at a machine tool so as to be movable in three axial directions, that is, an X-axis direction, a Y-axis direction, and a Z-axis direction; a rotating table is attached to the ram; and a spindle head is mounted to the rotating table. By this, the spindle head is mounted to the machine tool so as to be rotatable and so as to movable in the three axial directions (that is, the X-axis direction, the Y-axis direction, and the Z-axis direction). The spindle head has a frame, a main shaft, and a pair of support shafts. The frame has a pair of legs and is formed in a U shape. The main shaft supports a spindle and is disposed between the legs. The pair of support shafts are orthogonal to the main shaft. The pair of support shafts are provided on respective sides of the main shaft, are secured to the main shaft, and are coaxially formed with respect to each other. The pair of support shafts are rotatably supported at the pair of legs. One of the support shafts is connected to a motor. The motor is driven to rotate the support shaft. The rotation of the support shaft causes the main shaft to rotate. With the spindle being held at a predetermined rotation position by rotating the main shaft, a workpiece is processed by moving the main head by moving the ram. Depending upon circumstances, the workpiece may be processed by rotating the spindle by rotating the main shaft. The movement of the ram thereof in the three axial directions, that is, the X-axis direction, the Y-axis direction, and the Z-axis direction, the rotation of a motor of the rotating table, and the rotation of the motor of the support shaft are performed when a controlling device of the machine tool performs numerical control on the basis of programming. In the machine tool in which a processing table on which a workpiece is placed is movable, the processing table is moved by the controlling device of the machine tool performing numerical control on the basis of programming.
Patent Document 1: Japanese Patent No. 3761230